Railway-traffic-controlling apparatus



' Dec. 1, 1925- 1,563,819 H. s. YOUNG RAILWAY TRAFFIC CO TROLLINGAPPARATUS 2 Sheets-$heet 1 Filed Jan. 4, 1924 INVENTORZ V izm Dec. 1,1925' 1,563,819

H. s. YOUNG RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Jan. 4, 1924 2SheetsI-Sheet 2 INVE NTOFI 3 9% 61 maam Patented Dec. 1, 1925.

UNITEDSTATES PATENT OFFICE.

HENRY S. YOUNG, 0J3 WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNIONSWITCH & SIGNAL COMPANY, OF SWISSVALE, PENN$YLVANIA, A CORPORATION OFPENNSYLVANIA.

RAILWAY-TRAFFICCONTROLLING APPARATUS.

Application filed January 4;, 1924. Serial No. 684,293.

To all whom it may concern:

Be it known that I, HENRY S. YOUNG, a

citizen of the United States, residing: at VVilkinsburg, in the countyof Allegheny and State of Pennsylvania, have invented certain new anduseful Improvements in Railway-Traflic-Controlling Apparatus, of whichthe following is a specification.

' My invention relates to railway traffic controlling apparatus, and isparticularly well adapted for, though not necessarily limited to,apparatus for controlling tr aflic along stretches of single track overwhich trains move in both directions.

I'will describe two forms of apparatus embodying my invention, and willthen point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing oneform of apparatus embodying my invention, and Fig. 2 is a view showing amodification of the apparatus shown in Fig. 1, and also embodying myinvention.

Similar reference characters refer to similar parts in each of theviews.

Referring first to Fig. 1, the reference characters 1 and 1 designatethe track rails of a stretch of single track between two passing sidingsZ and Y. This stretch is divided by insulated joints 2 into a pluralityof track sections 5-6, 6-7, 78, 8-9 and 9 -10. Each section is providedwith a track circuit comprising a battery I) connected across the railsat one end of the section, and a track relay connected across the railsat the other end and designated by the reference character T with asuitable exponent. The middle section 78 is provided with an additionaltrack relay T at the battery end of the section.

Traffic moving from left to right is governed by two signals S and Slocated at points 5 and 7 respectively, whereas traffic moving fromright to left is governed by two signals S and S located at points 8 and10, respectively. It will be seen, therefore, that the intermediatesignals S and S are staggered in that they are located at opposite endsof the middle section 78.

Each signal is provided with a line relay designated by the referencecharacter H with the same exponent as that applied to'the signal, andeach of these relays is of the polarized type, so that it is responsiveto reversals of current. Referring to signal S, for example, this signalis provided with a caution indication circuit which passes from thepositive terminal of battery B through contact 29 of relay H operatingmechanism of signal S and contact 30 of relay H to the negative terminalof battery 13 This signal is also provided with a proceed indicationcircuit which passes from the positive terminal of battery B throughcontact 29, polar contact 31 of relay H operating mechanism of signal Sand contact 30 to the negative terminal of battery B The polar contact31 is closed only when relay H is'energiz ed by current of what I willternfnormal polarity;

Each of the remaining signals'S is controlled by its associated linerelay H in the manner above described. Line relay H for signal S isprovided with a' main circuit which passes from the positive terminal ofbattery 13, through wire 11, pole-changer P, contact 12 of track relay Tcontact 13 of track relay T winding of relay H common wire 0,pole-changer P back contact 14: of auxiliary relay X front contact 15 ofrelay H to the negative terminal of batter B Line relay H which controlssignal g is provided with a similar main circuit which passes from thepositive terminal of battery B through pole-changer P contact 16 oftrack relay T", contact 17 of track relay T winding of relay H commonwireO, pole-changer P back contact 18 of auxiliary relay X and frontconplained hereinafter in describing the operation of the apparatus.

Linerelay H is provided with a circuit which passes from a sourceofcurrent located to the right of point 10 and not shown in the drawing,through other apparatus also not shown in the drawing, then throughcontact 41 of track relay T contact 21 of track relay T back contact 22of relay X contact 23 of track relay T contact 24 of track relay Twinding of relay H, and common wire to the source of current to theright of point 10. Line relay H is similarly controlled by a contact 42of track relay T contact 25 of track relay T, back contact 26 of relay Xcontact 27 of track relay T and contact 28 of track relay T In so far asthe present invention is concerned, the only important factor in thecontrol of line relays H and H is that the circuit for relay H includesa back contact of auxiliary relay X and the circuit for relay H includesa back contact of the auxiliary relay X The operation of the apparatusshown in Fig. 1, is as follows: When a train moving toward the leftapproaches point 10, it causes signal S to assume the caution positionbecause .of reversal of the current in line relay H through the mediumof the apparatus located tothe right of point 10 but not shown in thedrawing. As such train passes point 10 it opens track relay T therebyopening the circuits for line relays H and H so that signals S and Smove to the stop position. The opening of line relay H opens the circuitfor line relay H so that signal S also assumes the stop position. As thetrain passes signal S it opens track relay T thereby closing a pick-upcircuit for relay X which circuitpasses from the positive terminal ofbattery B, through the winding of relay X back contact 32 of track relayT circuit controller 33 to the negative terminal of battery B Circuitcontroller 33 is closed from the proceed to the caution positions ofsignal S The opening of track relay T also opens the circuit for linerelay H so that signal S assumes the stop position, but auxiliary relayX becomes energized before circuit controller 33 opens. lV hile thispickup circuit,

is closed a stick circuit for relay X is closed, which circuit passesfrom the positive terminal of battery B through the winding of relay Xfront contact 34 of relay X circuit controller 36 36, to the negativeterminal of battery B Circuit controller 36"36 is closed from the 90 tothe 30 positions of signal S After signal S passes below the 30position, another stick circuit for relay X is closed, which circuit isfrom the positive terminal of battery B through the winding of relay Xfront contact 34, back contact 35 of relay H circuit controller 36 36,to the negative terminal of battery B Relay X will,

therefore, remain energized as long as relay H is de-energized. hen theentire train has passed out of section 89, so that track relay T becomesenergized, an auxiliary circuit is closed for line relay H which circuitpasses from the positive terminal of battery B through wire 11,right-hand arm of polechanger P (now reversed), common wire 0, windingof relay H track relay contacts 17 and 16, right-hand arm ofpole-changer P (now reversed), front contact 37 of relay X circuitcontroller 38 (closed only in the stop position of signal S wire 43,circuit controller 38 (closed only in the stop position of signal S andback contact 40 of relay X to the negative terminal of battery B Currentof reverse polarity is thus supplied to line relay H so that signal S assumes the caution position. As the train proceeds through sections 6-7and 5-6, no change occurs in the condition of the apparatus other thanthe successive operation of the several track relays, because line relayH is controlled up to and including track relay T When the train passespoint 5, line relay H again becomes energized so that signal S moves tothe caution position. The opening of line relay H also releasesauxiliary relay X so that line relay H is again placed under the controlof line relay H Inasmuch as signal S now occupies the caution position,signal S will indicate proceed. Signal S returns to the proceed positionbecause line relay H has again become energized. After the train passesa certain distance beyond point 5, line relay i will become energized innormal direction, so that signal S will return to the proceed position.Signal S remains in the stop position until the train passes point 5,because line relay H is controlled by back contact 22 of relay X andrelay X does not become tie-energized until the train passes point 5.

The operation of the apparatus during the passage of a train moving fromleft to right will be understood from the foregoing without furtherexplanation. The only difference to be noted is that the pick-up circuitfor relay X includes back contacts 44 of track relay T and 45 of trackrelay T in series.

I will now assume that a train passes through the stretch moving fromright to left, and that signal S sticks in the proceed or cautionposition as the train passes this signal. The operation will be the sameas before until the train enters section 78. The opening of track relayT will close the pick-up circuit for relay X as in normal operation, butthis latter relay will then remain energized due to its auxiliary stickcircuit including front contact 34 of relay X and circuit controller 3636. That is to say, auxiliary relay X will remain energized until thetrouble is removed. Signal S will remain in the stop position becausethe circuit for line relay H is open at circuit controller 38 on signalS, and also because this circuit is opened at back contact 37 of relay Xpole-changer P having remained in the normal position. Signal S willremain in the stop position because the circuit for relay H remains openat back contact 22 of relay X Signal S will remain in the stop positionbecause the circuit for relay H is open at contact 15 of relay H Itfollows, therefore, that if signal S sticks in the proceed or thecaution position, signals S S and S will remain at stop after a trainmoving toward the left passes through the stretch of track shown in thedrawing.

I will now assume that a train moving from right to left passes throughthe stretch of track, and that all parts of the apparatus functionproperly except that signal S sticks in the proceed or caution position.When the train passes signal S auxiliary relay X will become energizedas in normal operation, and when the train passes signal S auxiliaryrelay X will become energized, because its pick-up circuit is closed atback contacts 44 and 45 of track relays T and T Relay X will then remainenergized due to its stick circuit which includes contact 34 of relay Xand circuit controller 36-36 on signal S. That is to say, relay X willremain energized until the trouble is removed. Line relay I-I will thenremain deenergized because its circuit is open at back contact 26 ofrelay X and so signal S will remain in the stop position. Auxiliaryrelay X will therefore remain energized because its stick circuitthrough contact 34, back contact 35, and circuit controller 36 36remains closed. Signal S will remain in the stop position because thecircuit for line relay I is opened at circuit controller 38 on signal SSignal S will remain at stop because the circuit for line relay H isopen at back contact 14 of auxiliary relay X and also at front contact15 of line relay H (It will be noted that the circuit for line relay I-Iremains open at back contact 22 of relay X It follows, therefore, thatsignals S S and S will remain in the stop positions after the trainleaves the stretch of track shown in the drawing.

It will be clear from the foregoing that if both intermediate signals Sand S should stick in the proceed or caution position, the first trainmoving from siding Y to siding Z would leave the end signals S and S inthe stop positions, because the line relay H would remain open at backcontact 14 of relay X and the line relay H would remain open at backcontact 18 of relay X One feature of the apparatus shown in Fig. 1 isthat the auxiliary relays X and X are kept energized in order toaccomplish the desired protection. Each of these relays is picked up bya circuit which includes circuit controller 33 on the correspondingsignal. Under normal operation .paratus, and is the signal arm starts tomove from the proceed or the caution position as soon as the associatedline relay opens, and circuit controller 33 is closed only far enoughbelow the caution position to insure a good contact when the signal armis in the caution position. In other Words, circuit controller 33 isusually adjusted to open at about the 44 position of the signal. As thesignal arm moves below the 44 position, the asso ciated auxiliary relayX will be held energized for a brief time by its stick circuit includingcircuit controller 3636 and subsequently the auxiliary relay is held bya stick circuit including circuit controller 3636'. This arrangementconstitutes a check which insures that circuit controller 3636 functionsproperly each time that the signal moves to the stop position. If thiscircuit controller does not close or make contact as it should, theassociated auxiliary relay will be released and this would, of course,result in the failure of signal S or S to move to the caution positionafter a train passes signal S or S This check on the operation ofcircuit controller 3636 is desirable in order that this circuitcontroller may be depended upon to hold the associated auxiliary relayenergized in case of a failure of the associated signal to move to thestop position. Itwill also be noted that all wiring used in keeping theauxiliary relay energized in case of a signal failure, is used in thenormal operation of the aptherefore, checked during each such normaloperation.

Referring now to Fig. 2, in the apparatus here shown, the stretch oftrack between passing sidings Z and Y is divided into six track sections5-6, 67, 1011. A pair of opposing signals S- and S is located at point 7and another pair of opposing signals S and S is located at point 9. Eachsignal is controlled by its associated line relay H in the same manneras in Fig. 1.

Line relay H for signal S is provided with a main circuit which passesfrom the positive terminal of battery B thro-ughthe right-hand arm ofpole-changer P back contact 46 of auxiliary relay X, front contact 47 ofrelay H contact 48 of track relay T, contact 49 of track relay T windingof relay H common wire 0 and the left-hand arm of pole-changer P to thenegative terminal of battery 13.

Line relay H for signal S is-provided with a similar main circuit whichis controlled by pole-changer P back contact 50 of auxiliary relay Xfront contact 51 of relay H and contacts 52 and 53 of track relays T andT respectively.

Line relay H for signal S is provided with a main circuit which passesfrom the positive terminal of battery B, through the right-hand arm ofpole-changer P back contact 54- of auxiliary relay X front contact 55 ofrelay H, contact 56 of track relay T back contact 57 01 relay X contact58 of track relay T winding of relay H common wire 0 and the left-handarm of polechanger P to the negative terminal of battery 15.

Line relay H for signal S is provided with a similar main circuit whichpasses from the positive terminal of battery B through the left-hand armof pole-changer P back contact 59 of relay X frontcontact 60 of relay Hcontact 61 of track relay T, back contact 62 of relay X, contact 63 oftrack relay T winding of relay H common wire 0 and the right-hand arm ofpolechanger P to the negative terminal of battery B The circuit for linerelay H associated with signal S is from a source of current located tothe right of point 11 and not shown in the drawing, through the contact(54 of track relay T back contact 65 of relay X contact 66 track relay Twinding of relay H and common wire 0 to the same source of current.

The circuit for line relay H associated with signal S similarly passesfrom a source of current to the left of point 5 and not shown in thedrawing, through contact 6? of track relay T back contact 68 of relay Xcontact (39 of track relay T, winding of relay H and common wire 0 tothe same source of current.

The operation of the apparatus shown in Fig! 2 during the passage of atrain moving from right to le'l't is as follows:

Prior to passing point 11 such train causes the polarity of the currentsupplied to line relay H to be reversed, so that signal S moves to thecaution position. When the train passes point 11 it opens track relay Tthereby opening the circuit for line relay H so that signal 5 moves tothe stop position. The opening of track relay T also opens the circuitfor line relay H", so that signal S moves to the stop position, and thisin turn causes signals S and S to move to the stop positions owing tothe step-by-step control of these three signals.

As the train passes point 9, it closes the pick-up circuit for auxiliaryrelay X which circuit passes from battery 15 through the winding ofrelay X circuit controller 33 on signal S back contact 70 of track relayT, back contact 71 ct track relay T to the negative terminal of batteryB Alter relay X becomes closed, a primary stick circuit for relay X isclosed, which circuit passes from the positive terminal of battery Bthrough the winding of relay X front contact '22 of relay X circuitcontroller {$3=($" on signal S, to the negative terminal of battery B.After circuit controller 3(3S6 becomes opened and circuit controller3636 becomes closed, a second stick circuit is closed for relay X whichcircuit is from the positive terminal oi battery B through the righthandarm oi pole-changer l (now reversed), common wire 0, left-hand arm ofpole-changer P (now reversed), the winding of relay X front contact 72,circuit controller 3(i36 back contact 73 of relay H back contact T l ofrelay H circuit controller 3(S36 on signal S, and back contact 7 5 ofrelay X'", to the negative ter minal of battery B Auxiliary relay Xbeing energized, an auxiliary circuit is closed for line relay H, whichcircuit passes from positive terminal of battery B, through theleft-hand arm of pole-changer P common wire-O, winding of relay Hcontact 53 of track relay T contact 52 of track relay T, circuitcontroller 38 on signal S, front contact 50 of relay )1, and theright-hand arm of polechanger P to the negative terminal of battery BThe current thus supplied to line relay H is of reverse polarity, sothat signal S moves to the caution position.

As the train passes point 7, it opens track relay T thereby placingsignal S in the stop position, and while the track relays T and T areboth open, the pick-up circuit for auxiliary relay X is closed throughcircult controller 33 on signal S and back contacts 76 and 77 of trackrelays T and T", respectively. The primary holding circuit for relay Xincludes contact 79 of this re lay and circuit controller 3(3"36 onsignal S The final holding circuit for relay X includes contact 79, backcontact 78 of relay H and circuit controller 36"36 on signal S lVithauxiliary relay X energized, an auxiliary circuit is closed for linerelay H which circuit passes from the positive terminal of battery Bthrough the left-hand rm of 'pole-changer P common wire 0, winding ofrelay H contact 63 of track relay T back contact 62 of auxiliary relayX", contact 61 of track relay T circuit controller 38 operated bysignal. S front contact 59 of relay X and the righthand arm ofpole-changer P", to the negative terminal of battery B The current thussupplied to relay H is of reverse polarity, so that signal S moves tothe caution position as soon as trark relay T'" closes. Signal Sthereupon returns to the proceed position and relay opens because itsfinal holding circuit is now opened at back contact 73 of relay Afterthe entire train has passed point 5, signal 55 returns to the cautionposition so that auxiliary relay X opens and signal S returns to theproceed position. After the train passes a given point to the left ofpoint 5, signal S returns to the proceed position,

During the passage of such train from siding Y to siding X, signal Sreturns ,to the proceed position as soon as relay X opens, that is, assoon as the rear end of the train passes point 7. Similarly, signalsreturns to the proceed position as soon as relay X opens, that is, assoon as the rear of the train passes point 5. Signal S also returns tothe proceed position when the rear of the train passes point 5.

The operation of the apparatus during the passage of a train moving fromleft to right will be understood from the foregoing without furtherexplanation.

I will now assume that a train moving from right to left passes throughthe stretch of track shown in the drawing, and that signal S sticks inthe proceed or caution position. When the train passes point 9 relay Xwill close, because circuit controller 33 in its pick-up circuit isclosed, and this relay will thereafter remain closed on its primarystick circuit until the trouble is removed. Relay H is then held open atback contact 62 of relay X so that signal S will remain at stop. Relay Hwill be held open at circuit controller 38 on signal S and also atcontact 51 of relay I so that signal S will be held at stop. Relay Hwill be held open at the left-hand arm of polechanger P because thispole-changer remains in the normal position, and this relay will also beheld open at back contact 54 of relay X so that relay S5 will remain atstop. Relay H will remain open because relay H and relay X are bothopen, and so signal S will remain at stop. It follows, therefore, thatafter a train moving from right to left passes through the stretch oftrack and signal 3 remains in the proceed or caution position, signals SS", S and S will remain at stop.

I will now assume that signal S sticks in the proceed or cautionposition and that a train moving from right to left passes through thestretch of track shown in the drawing. Relay X will remain closed on itsprimary stick circuit until the trouble is removed. The circuit forrelay H will remain opened at the back contact 65 ofrelay X so thatsignal S will be held at stop. Relay H will remain open because itscircuit is open at relays H" and X", so that signal S will remain atstop. Relay H will remain open because relays H and X are open, so thatsignal S will remain at stop. Relay H will remain open because circuitcontroller 38 on signal S is open, and also because its circuit is openat pole-changer P and at back contact 50 of relay X. It follows thatsignals S S", S and S will remain at stop after the train has passedthrough the stretch of track.

If signal S sticks in the proceed or caution position, then when a trainmoving from right to left passes point 9, relay X 9 will close due toits pick-up circuitand will remain closed as long as its primary circuitis closed, but the final stick circuit for this relay will be open atcircuit controller 3636- on signal S and so relay H will remain open aslong as relayH is open. When the train passes point 7 relays X and Xwill both close, and relay X will then remain closed on its primarystick circuit, until the trouble is removed. Relay H will remain open atback contact 68 of relay X so that relay X will likewise remain closeduntil the trouble is removed. Rela H will remain open at contact 57 ofrelay 9& so that signal. S will remain at stop. Relay H will remain openat circuit controller 38 on signal S and also atcontact 60 of relay H sothat signal S will remain at stop. Relay H will remain open atpole-changer P so that signal S will remain at stop. It follows thatsignals S S S and S will re-' main at stop after a train moving towardthe left has passed through the stretch of track- If signal S sticks inthe proceed or vcaution position, then when a train passes point 7 relayX will close and will remain closed due to its primary stick circuituntilthe trouble'is removed. RelayjH will then be held open bypole-changer P so that relay X will remain closed, with the result thatsignal S will remain at caution. Signal S however, will remain at stopbecause relay H is open. Relay H willv remain open because its circuitis open at relay 'X and also at relays H and X so that signal S willremain at stop. Relay H will remain open because relay X remains closed,and so signal S will remain at stop. Relay H will remain open becausecircuit controls ler 38 on signal S is open and also because relays Hand X areboth open. It follows that signals 8, S S and S will remain atstop after a train moving from. right to left has passed out of thestretch of track.

It will be clear fromthe foregoing that if both signals S and S shouldsimultaneously stick in the proceed or caution positions, the firsttrain passing through the stretch from right to left would leave signalsS S and b at stop; similarly, if signals S and S should simultaneouslyfail in the proceed or caution position, the first train passing throughthe stretch from right to left would leave signals S S and S at stop.Further analysis will show that in the eventof any .combination of clearfailures of intermediate signals, one or more signals governing trafficin each direction will remain at stop after the first train has passedthrough the stretch from siding to siding.

Although I. have herein shown and-dc scribed only two forms of apparatusembodying my invention, it isunderstood that various changes. andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what Iclaim is:

1. In combination, two successive signals governing traffic in the samedirection, a line relay for the forward signal, a main circuit for therear signal controlled by a front con tact of said line relay, anormally de-energized auxiliary relay associated with said forwardsignal, means for energizing sa d auxiliary relay when a train moving insaid direction passes said forward signal, a circuit controllerassociated with said forward signal and closed only when the signalindicates stop, and an auxiliary circuit for said rear signal controlledby a front contact of said auxiliary relay and by said circuitcontroller.

2. In combination, two successive signals governing traffic in the samedirection, a normally energized line relay and a normally de-energizedauxiliary relay associated w1th the forward signal, a main circuit forthe rear signal controlled by a front contact of said line relay and aback contact of said auxiliary relay, means for energizing sa dauxiliary relay when a train moving in sa1d direction passes saidforward signal, a circuit controller associated with said forward signaland closed only when the signal indicates stop, and an auxiliary circuitfor sa1d rear signal controlled by a front'contact of said auxiliaryrelay and by said circuit controller.

3. In combination, two successive signals governing traffic in the samedirection, a normally energized line relay and a normally ale-energizedauxiliary relay associated with the forward signal, a main circuit forthe rear signal including a front contact of said line relay and a backcontact of said auxiliary relay, means for energizing said auxiliaryrelay when a train moving in said direction passes said forward signal,and an auxiliary circuit for said rear signal controlled by a frontcontact of said auxlliary relay.

4;. In combination, two successive signals governing traffic in the samedirection, a normally de-energized auxiliary relay asso ciated with theforward signal, means for energizing said relay when a train moving insaid direction passes the forward signal, and means for causing saidrear signal to give a proceed indication. when said auxiliary relay isenergized if the forward signal indicates stop but not if the forwardsignal gives any other indication.

5.- In combination, a rear and a forward signal governing traffic in onedirection, a third signal governing traffic in the opposite direction, anormally de-ener 'ized auxiliary 0 o I c relay associated with saidforward signal,

means for energizing said relay when a train passes said forward signalmoving in the direction in which such signal governs traffic, and meansfor preventing said rear signal from giving a proceed indication whensaid auxiliary relay is energized unless said third signal indicatesstop.

6. In combination, a rear and a forward signal governing traffic in onedirection, a third signal governing traffic in the opposite direction, anormally de-energized auxiliary relay associated with said forwardsignal, means for energizing said relay when a train passes said forwardsignal moving in the direction in which such signal governs traffic, andmeans for preventing said rear signal from giving a proceed indicationwhen said auxiliary relay is energized unless said forward signal andsaid third signal both indicate stop.

7. In combination, a rear and a forward signal governing traffic in onedi rection, a third signal governing traftie in the opposite direction,a normally deenergized auxiliary relay associated with said forwardsignal, means for energizing said relay when a train passes said forwardsignal moving in the direction in which such signal governs traffic, anormally de-energized auxiliary relay associated with said third signal,means for energizing said second auxiliary relay when a train passes thethird signal moving in the direction in which such signal governstrafiic, and means for preventing said rear signal from giving a proceedindication when said first auxiliary relay is energized unless saidforward signal and said third signal both indie-ate stop and said secondauxiliary relay is deenergized.

8. In combination, a rear and a forward signal governing traffic in onedirection, a third signal governing traffic in the opposite direction, anormally energized line relav and a normally de-energized auxiliary relay associated with said forward signal, a main circuit for said rearsignal controlled by a front contact of said line relay, two circuitcontrollers associated with said forward signal and said third signalrespectively and each closed only when the associated signal indicatesstop, means for closing said auxiliary relay when a. train passes saidforward signal moving in the direction in which such signal governstraffic, and an auxiliary circuit for said rear signal controlled by afront contact of said auxiliary relay and by both of said circuitcontrollers.

9. In combination, two signals governing traffic in opposite directions,a normally tie-energized auxiliary relay associated with each signal,means for energizing each auxiliary relay when a train passes theassociated signal moving in the direction in which such signal governstraffic, a holding circuit for each auxiliary relay including a frontcontact thereof and a circuit controller closed at all times except whenthe associated signal indicates stop, and means for causing each signalto indicate stop when the auxiliary relay for the other signal isenergized.

10. In combination, two signals governing traffic in oppositedirections, a normally de-energized auxiliary relay for each signal,means for energizing each of said relays When a train passes theassociated signal moving in the direction in which such signal governstraliic; a main stick circuit for each relay controlled by a frontcontact thereof, and by a circuit controller actuated by each signal andclosed only when the associated signal indicates stop; an auxiliarystick circuit for each relay controlled by a front contact thereof andby a circuit controller closed when the associated signal does notindicate stop, and means for controlling each signal by a back contactof the auxiliary relay for the other signal.

11. In combination, a signal, a normally de-energized auxiliary relayassociated with said signal, means" for energizing said relay when atrain passes said signal moving in the direction in which the signalgoverns traffic and for also energizing said relay when atrain passesthe signal moving in the other direction if the signal sticks in aproceed position, a holding circuit for said relay including a frontcontact thereof and a circuit controller closed when the signal is in aproceed position, and a second signal con trolled by said auxiliaryrelay.

12. In combination, two signals governing traffic in oppositedirections, a normally deenergized auxiliary relay associated with eachsignal, means for energizing each relay when a train passes theassociated signal moving in the direction in which the signal governstrafiic and for also energizing each relay when a train passes theassociated signal moving in the opposite direction if the signal sticksin a proceed position, a holding circuit for each relay including acircuit controller closed when the associated signal is in a proceedposition, and means for causing each signal to indicate stop when theauxiliary relay for the other signal is energized.

In testimony whereof I aflix my signature. I

HENRY S. YOUNG.

